The present application claims priority to Provisional Application Serial No 60/193,672 filed Mar. 31, 2000 and entitled xe2x80x9cFOUR LAYER DAMPED COVERxe2x80x9d.
The present invention relates to a disc drive having rotating or reciprocating operating components. In particular, the present invention relates to a cover having multiple cover plates with damped layers for damping vibration for acoustic noise control for a disc drive.
Disc drives provide data storage for digital information on discs. Discs are supported on a spindle hub which rotates about a spindle shaft to form a spindle assembly. An E-block assembly supports heads relative to discs to read data from and/or write data to the discs. The E-block assembly is rotationally supported relative to an E-block shaft to move heads for head placement relative to selected data tracks on surfaces of the discs. Rotation of the spindle hub and E-block about the spindle shaft and E-block shaft introduces vibration to the disc drive which produces acoustic noise.
With drive capacity increasing and form factor dimensions decreasing, disc drive embodiments have secured the spindle shaft and E-block shaft to covers secured to the base chassis of the disc drive. Thus, vibration introduced via rotation of the spindle hub and E-block is transmitted to the cover through the connections between the spindle shaft and E-block shaft and the cover. Vibration of the cover produces acoustic noise. The present invention addresses these and other problems and provides advantages and solutions not previously recognized.
The present invention relates to a cover for a disc drive assembly including a composite structure. The cover includes multiple cover plates including a first cover plate and a second cover plate. Each of the first and second cover plates includes at least one structural layer formed of a relatively rigid material and at least one damped layer to provide a cover with multiple damped cover plates.